Improvement in dynamo-electric machines



4 sheets-sheen 1.

E. WESTON. Dynamo-Electric Machine.

Patented oct. 29,1878.y

l Navel/vv,

N.PETERS, PHOTO-LHHOGRAPHER. wAsmNGroNA D c,

4 Sheets-.Sheet 2.. E. WE S T O N.

Dynamo-Electric Machine.

No. 209,532. Patented Oct. 29,1878.

4 Sheets---Shee'fu 3.

Patented Oct. 29,1878.

E. WESTON. Dynamo-Electric Machine. No. 209,532.

4 Sheets--Sheet 4.

E. WESTON. Dynamo-Electric Machine.

Patented oct. 29, 187e...l

UETTED STATES FIYWRI) VESTON, OF NEVARK, NEV JERSEY, ASSIGNOR 'IO WESTON DYNAMO-ELEOTRIO MACHINE COMPANY, OF SAME PLACE.

HVIPROVEMENT IN DYNAMO-ELECTRIC MACHINES.

Spccilication forming part of Letters Patent No. 209,532, dated October 29, 1878; application liled June 4, 1878. i

CASE D.

To all whom it muy concern Be it linown that I, EDWARD VESTON, of Newark, New Jersey, have invented certain Improvements in DynamoFlectric Machines, et' which the following is a specification My improvements relate to that class of dynamo-electric machines in which a system or systems ci' coils which longitudinally traverse an armature rotating in the magnetic iield hetwcen the poles of two stationary electro-inagncts are included in circuit with the coils surrounding the stationary magnets and my invention consists, iirst, in providing' for the rotatin g coils a skeleton core, or, in otherwords, a core the outer portion of which is rendered discontinuous hy a series of deep transverse grooves and hy a longitudinal groove or slit extending from one end of the armature to the other. instead oi' making the core of a single pi ce ot' iron it may he more conveniently constructed hy mounting upon the armature-shaft a series er" iron disks, separated from eachother hy intervening collars upon the same shaft. I use, preferably, a hollow shaft for the armature, and here holes radially through the collars into the shaft for the purpose of providing a path for the circulation of air from the hollow shaft into the spaces between the disks, from which such air is discharged, when the armature is rotated, through the nterstices in the coils which traverse its exterior. I also here one or more holes through the disks for the purpose of connecting the air-spaces with each other and with air-chambers established at the ends ot' the armature, so that air may he supplied not only through the shaft but through the openings in the outer walls of the air-chambers. There are two advantages resultin from this mode of construct-ing the armaturecore First, there is a vigorous circulation et' air through Athe core when the armature is rotated, which tends to keep the machine cool; and, secondly, owing to the discontinuity oi' the outer portion of the core, there is no metallic path completely around the core in any direction wherein rotary currents et electricity can he established hy induction.

The second feature of my invention consists in successively winding upon the armature two systems of coils, one overlying the other, cach system hein g wound in dia-metrically-sepa: rate divisions, and each division being connected to the next adj oinin division hy a loop, the bight of which is connected to one `of the commutator-strips. The two'frec ends of each system of coils are respectively connected to the same two diametrically-opposite strips ot' the coinmutator. 'Ihe two systems of coils are thus connected, with each other as it they were composed of an endless wire. In the eX- ample of this mode of winding the coils shown in the drawings, I have wound each system of coils in four divisions, and I thus have eight loops for connection with the commutator, which accordingly has eight separately-insulated strips. In ett'ect, two currents, generated in two parallel wires, are communicated to the two strips which are in contact with the brushes, and the whole double system ot' coils is constantly employed in the generation of the current.

It is an incidental feature of this part of my invention that the loops or wires connecting the coils with the commutator-strips are all carried through one of the journals of the armature-shaft, either through a bushin g of insulating material inscrted in a metallic shoulder, or collar upon the armature-shaft.

The third feature of my invention consists in combining with the machine a condenser, the opposite sides of which are connected respectively to the two binding-posts, whereby the variations in the strength of the current generated by the rotation et' the armature are compensated for by the charge and discharge oi' the condenser.

rIhe accompanying drawings are as follows:

Figure l is an isometrical perspective of the machine. Fig. 2 is an cud view ot' the armature-core detached from the machine. Fig. 3 is a central longitudinal section of the armature-core. Fig. a is a transverse section oi' the armature through the line 0 a; on Fig. 3. Figs. 5 and G are diagrams for illustrating the inode of winding the double system of armature-coils. Fig. 7 is a transverse section of that one of the armature-jonrnals through which the connecting-wires pass from the Vcoils Fig. 8 is an iso.

The upperends/Jthese cores are bolted to the cross-piede B2, and the coils B3 are so wound upon the vertical cores that the laterally-projecting poles b and bl are of opposite pol'arities. The inner faces of the poles b and I)l are concave, and just clear the periphery of the revolv- /ing armature.

The poles, it will be seen, are each provided with a series of parallel slots, b2, the object of these slots being to provide passages for the escape of air drawn into the rotating armature through the holes in its ends and ejected therefrom through the interstices in the coils traversing its exterior.

The armature-core C may be made of a single piece of metal, or it may be built up of separate pieces, as shown in longitudinal section in Fig. 3. In the latter case the core consists of two end pieces, c c, centrally mounted upon a preferably hollow shaft, O. Between the two end pieces, and centrally mounted upon the same shaft, are a series of disks, D, which are separated from each other by the collars d. The end pieces, collars, and disks are clamped together by means of the nuts E E, which respectively engage screw-threads on the projecting portions of the shaft, and the heads, disks, and ends may be keyed together by means of the key-pin e.

It will be seen that holes F are bored radially through the collars d into the hollow shaft C', so that air drawn into the hollow shaft when the armatureis rotated may be discharged therefrom into the spaces f between the disks.

Several holes, G, extending longitudinally through the core, are bored through the end pieces and the disks. The outer ends of the core are recessed to form the air-chambers g g. The outer walls of these chambers are formed by the flanged tubes g1 g. The flan ged tubes gl are madel larger than the shaft G', and an annular opening, g2, is thus provided, through which air may be drawn into the chamber g, and thence through the longitudinal holesG into the spaces between the disks.

The object of the Ilan ged tubes g' is to spread the coils where they pass over the ends of the core, and thus keep them clear of the shaft C and provide the annular opening g2 for the passage of air into the airchambers g. The end pieces c of the core and the disks are provided with the polar extensions H, which separate the divisions of the coil from each other, and thus leave spaces "between the coils for the escape of air from the recesses in the core.

'My` core is longitudinally bisected by the slit t, for the purpose of preventing the establishinent by induction of rotary currents in the disks or in the end pieces.

It will be seen that the armature-coreis divided into eight sections, and is therefore adapted to carry four diametrically-separate V divisions of coils.

In my invention the coils on the armature are practically composed of an endless wire; but they may' be most conveniently considered and described as two similar systems of coils, the free ends of which are connected with each other. Fig. 5 is a diagram representing these coils as they would appear if their free ends were disconnected vfrom each other and if the coils were detached from the core and laid alongside of each other upon a flat surface. One system of coils is represented by the full lines, and the other system by the dotted lines. The heavy black lines J Jl J 2 J 3, within the i groups of coils, are arbitrary representations of the core. an arbitrary representation of the end of the armature,"showing the relative positions of the several divisions of the coils, and also showing `Lthe loops for connection with the commutator.

Similar letters of reference used in Figs. 5 and 6 indicate certain like parts which appear in both ligures.

In tracing the mode of winding it will be convenient to start from the top of Fig. 5, at-

loop, ll, is left for connection with one of the commutator-strips, and the wire is then wound upon the next adjoining division of the core in a plane Vat an angle of fortytive degrees, as lrepresented by the lines j. Having completed the number of turns on this angle I then form the loop l2, and proceed to wind the wire longitudinally around the core .in the horizontal plane represented by the lines y?. I then form the loop Z3, and carry the wire around the next division of the core on the reverse angle of forty-five degrees, as represented by the lines jf.. After having completed the number of turns around this division of the core I bring out the free end 14, which is then to be connected with the free end m of the other system of coils, or, in other words, connected to that strip of the commutator with which the free end m is connected.

To trace the course of the other system of coils, commence near the top of Fig. 5, at m.,

-whence the wire proceeds, as'indicated by the dotted line, overlapping the vertical division of the first system of coils, and after having made the proper number of turns forming the Fig. 6. is

loop m1, ironi which the wire is carried to the next division, and is there wound longitudinally, overlapping the division ot tho iirst coil, which is wound on an an gle oi'iorty-tive degrees. The loop m2 is then formed, and the wire is carried to the next division, whereit is wound in a horizontal plane, overlapping the iirst coil, and is thon brought out to form the loop m3, from which it is carried around the last division ot' the 'lirst coil-that is, in a plane at a reverse an glo oil tort-y-iive degrees, and the free end mi is carried out and connected with the free end l ot the iirst system of coils, or, in other words, is connected with that strip of the commutator with which the free end l is connccted.

Each loop is connected with a separate strip of the commutator, the loop of each division of the iirst system oi coils being connected with the connnutator-strip, which is diametrieally opposite to the strip which is connected with the loop of the overlapping coil of the same division. For example, the loop ll is connected with the connnutator strip diametrically ojposite the strip with which the loop m1 is connected, and so on. Assuming one ot' the brushes to be in contact with that strip ot' the commutator with which the loop ZI is connected, and the other brush to bein contact with the strip diametrically opposite with which the loop m1 is connected, and assuming that the loop 1 is positive and the loop m1 is negative, the direction otl the currents siinultaneously generated in the coil is indicated by the arrow-heads, from which it will be seen that two currents, startingi'rom the loop Z, diverge and pass in opposite directions through the double system ot' coils and moet in the loop m1, by which they are conveyed to the commuiator-strip immediately opposite that with which the loop ll is connectedn lt will thus ie seen. that the whole of the double system oil' coils is utilized for the production et' each electriealimpulse collected by the brushess ily commntator il (sce Fig. S) consists ot' a cylinder *novide i with eight separately-insulated strips, n, and the 'divisions abetween the strips, instead ot' being parallel with the axis ot' the con ator, as usual, are slightly inclined thenV i, or spiral. rllhere is therefore no b in the Acircuit as the comunitator revoli es, L/ecause the brushes, before they lose contact with one strip, acquire contact with the next following strip; and this arrangement ot' the commutator with reference to the brushes, and in connection with armature-coils wound in the peculiar mode dcscribcd, results in the production, by my machine, ot a continuous current.

rihe continuity ot the current results from the tact that when, for example, the positive brush is in eontac l with the two loops ll and Z2, and the negative brush is in contact with the two loops mi and m2, the diagonal divisions 9'1 ot' 'the coils are alone short-circuited,

the other divisions remaining more or less active in the generation ot' the current.

rlhe bearings for the shaft C are formed in the cross-pieces i) Gf, and the journal l) at the eommutaror end ot the shai't is made suiliciently large for the insertion or' eight tubes of insulating material, p, te contain the loops which connect the several strips of the commutator with the armature-coils.

At some convenient point on the machine, usually between the binding-posts, l arrange the condenser it, the opposite sides ot' which are connected respectively to the two bindingposts by the wires r i.

I do not deem any special description of the condenser necessary, as such forms ot' apparatus are well known and in common use i'or various purposes.

ln machines of the class to which mine belongs there is some diminution in the strength of the current, due to the cutting' out or shortcireuiting ot' one division of the coils at the instant when the brushes are in contact with two adjoining strips of the commutator, The condenser, charged bythe current at its highest strength, is partially discharged when there is a diminution in the strength of the current, and its discharge thus tends to equalizo the strength of the current in the operative part ofthe circuit. L

l claim as my invention in a dynamo-electric machinel. An armature-core having formed in it a series of recesses extending inward from its periphery, in combination with holes extending longitudinally through the coro trom one end to the other, substantially as and for the purposes set iorth.

2. An armature-core composed of a series ot short cylinders or disks mounted at intervals upon a common shaft and bisected from their peripheries to a line near their centers, substantially as and ior the purpose set forth.,

3. in armature-core composed of a series of disks separated from each other by collars, substantially as described, and mounted upon a hollow shaft, and provided with holes bored radially through the shai't and the collars i'or allowing air to be drawn through the shaft and discharged into the spaces between the disks when the armature is rotated, substantially as and for the purpose set forth,

.An armature, substantially such as de scribed, provided at its ends with the airchambers G, the outer walls of which are formed by the iianged tubes g1 provided with openings, substantially as shown, for the admission ot' air into such air-chambers and its discharge through the end pieces c into the spaces between the disks, substantially as and for the purpose set forth.

5. An armature wound with a double system oi'coils in diametrically-separate divisions, such divisions being looped together and the loops connected with the eoinmutator-strips, substantially as shown and describedB .6. A double system of armature-coils Wound and connected substantially as shown and described, in combination With a commutator composed of separately-insulated strips di- Videdfrom each other on lines atl an angle to the axis of the commutator-shaft, and two brushes, each adapted to hold contact with one strip until after it has acquired contact with the next adjoining strip, substantially as and for the purposes set forth.

7. A rotating armature having a recessed core with openings in its ends and in its periphery, in combination with the slots b2 in the poles of the stationary magnets, substantially as and for the purpose described.

8. Independently-insulatedV wires or loops connecting the armature-coils with the com- EDWARD WESTON.

Witnesses:

M. L. ADAMS, E. H. WILLIAMS. v 

